Sound source identifying and measuring apparatus, system and method

Abstract

A sound source can be identified and measured for a long time period outdoors and indoors. A sound source identifying and measuring apparatus including a baffle provided with a frame and a weather-resistant screen for providing an aerial clearance is used for long-term indoor and outdoor measurement at a sound source measurement location to acquire sound source information in all the directions and associate the azimuth, elevation, sound pressure information and/or frequency characteristics or the like per elapsed time. A directional digital filter as well as identification parameters of a target sound source and untargeted sound source are used to identify the sound source more accurately for identification and measurement of the target sound source. Contribution of all of a plurality of sound sources to a sound pressure level is separated in terms of the coming direction for analysis. Thus, whether or not the sound source is a target sound is determined, and determination such as estimation of its sound source intensity and sound pressure level is made.

1 . A sound source identifying and measuring apparatus for identifying a target sound source among untargeted sound sources comprising:
 a baffle formed into a sphere, a hemisphere, or a polyhedron;   a plurality of microphones having a sound collection section on the surface of the baffle; and   a weather-resistant screen formed to cover the outer surface of the baffle.   
     
     
         2 . The sound source identifying and measuring apparatus according to  claim 1 , comprising:
 a frame providing an inner frame and an outer frame, which contacts with the outer surface of the baffle on the inner frame side; and   a weather-resistant screen contacting with the outer frame and covers the outer surface of the baffle through an aerial clearance.   
     
     
         3 . The sound source identifying and measuring apparatus according to  claim 1 , comprising a bandpass filter and/or a filter specialized for a target sound source in a receiving system of the microphones. 
     
     
         4 . The sound source identifying and measuring apparatus according to  claim 1 , wherein the microphones each have waterproof or drip proof property, and/or,
 a seal member is provided between the baffle and microphones.   
     
     
         5 . The sound source identifying and measuring apparatus according to  claim 1 , comprising a level adjuster for setting the vertical direction height of the baffle relative to the installation position. 
     
     
         6 . The sound source identifying and measuring apparatus according to  claim 1 , characterized by comprising a direction adjuster for setting an azimuth reference line and an elevation reference plane of the baffle. 
     
     
         7 . A sound source identifying and measuring system, comprising:
 the sound source identifying and measuring apparatus as claimed in  claim 1 ;   an A/D converter that converts an analog signal which is a sound pressure signal around the baffle obtained through the microphones into a digital signal; and   the sound source identifying and analyzing apparatus that performs identification of the sound source direction, estimation of a sound pressure level for each sound source, and analysis of the moving path and moving speed of the sound source.   
     
     
         8 . The sound source identifying and measuring system according to  claim 7 , wherein
 the sound source identifying and analyzing apparatus has a calculation processing section, and   the calculation processing section performs numerical calculation to apply directional digital filtering to a digital signal.   
     
     
         9 . The sound source identifying and measuring system according to  claim 7 , wherein
 the sound source identifying and analyzing apparatus has an input section, and   the input section receives as an input target sound source identification parameter and/or untargeted sound source identification parameter to select the target sound source and/or exclude the untargeted sound source.   
     
     
         10 . The sound source identifying and measuring system according to  claim 7 , wherein
 image information corresponding to the coming direction of specified sound is captured, and image processing is performed in the sound source identifying and analyzing apparatus based on the captured image information so as to identify an object as a target sound source.   
     
     
         11 . The sound source identifying and measuring system according to  claim 7 , further comprising an omnidirectional noise measuring apparatus. 
     
     
         12 . The sound source identifying and measuring system according to  claim 7 , further comprising a radio altimeter signal wave receiver and/or a transponder response signal wave receiver. 
     
     
         13 . A sound source identifying and measuring method for identifying a target sound source from one or a plurality of untargeted sound sources comprising:
 a determination step of determining a time range corresponding to an analysis section in which the analysis of all coming directions of sound and intensity thereof are performed;   an analysis step of analyzing the time-frequency acquired from the microphones;   a search step of performing sound source search in the analysis section by performing the analysis of the all coming directions of sound and the intensity thereof;   a grouping step of classifying sound sources into sound source groups in terms of a frequency based on the sound source search result obtained for each sound source;   a determination step of determining a target sound source group among the sound source groups using a target sound source identification parameter and/or untargeted sound source identification parameter; and   an estimation step of estimating the time variation of sound for each sound source group.